Jorge Bergoglio of Argentina becomes Pope Francis

VATICAN CITY - Pope Francis put his humility on display during his first day as pontiff Thursday, stopping by his hotel to pick up his luggage and pay the bill himself in a decidedly different style of papacy than his tradition-minded predecessor, who tended to stay ensconced in the frescoed halls of the Vatican.

The break from Benedict XVI's pontificate was evident even in Francis' wardrobe choices: He kept the simple pectoral cross of his days as bishop and eschewed the red cape that Benedict wore when he was presented to the world for the first time in 2005 - choosing instead the simple white cassock of the papacy.

The difference in style was a sign of Francis' belief that the Catholic Church needs to be at one with the people it serves and not imposing its message on a society that often doesn't want to hear it, Francis' authorized biographer, Sergio Rubin, said in an interview Thursday with The Associated Press.

See photos from St. Peter's Square at http://www.wcpo.com/gallery/news/news_photo_gallery/Jorge-Maria-Bergoglio-named-new-pope

"It seems to me for now what is certain is it's a great change of style, which for us isn't a small thing," Rubin said, recalling how the former Cardinal Jorge Bergoglio would celebrate Masses with ex-prostitutes in Buenos Aires.

"He believes the church has to go to the streets," he said, "to express this closeness of the church and this accompaniment with the people who suffer."

Francis began his first day as pope making an early morning visit in a simple Vatican car to a Roman basilica dedicated to the Virgin Mary and prayed before an icon of the Madonna.

He had told a crowd of some 100,000 people packed in rain-soaked St. Peter's Square just after his election that he intended to pray to the Madonna "that she may watch over all of Rome."

He also told cardinals he would call on retired Pope Benedict XVI, but the Vatican said the visit wouldn't take place for a few days.

The main item on Francis' agenda Thursday was an inaugural afternoon Mass in the Sistine Chapel, where cardinals elected him leader of the 1.2 billion-strong church in an unusually quick conclave.

Francis is expected to outline some of his priorities as pope in the homily. The Vatican said it would likely be delivered in Italian, another break from the traditional-minded Benedict whose first homily as pope was in Latin.

Francis, the first Jesuit pope and first non-European since the Middle Ages, decided to call himself Francis after St. Francis of Assisi, the humble friar who dedicated his life to helping the poor.

The new pope, known for his work with the poor in Buenos Aires' slums, immediately charmed the crowd in St. Peter's, which roared when his name was announced and roared again when he emerged on the loggia of the basilica with a simple and familiar: "Brothers and sisters, good evening."

By Thursday morning, members of his flock were similarly charmed when Francis stopped by the Vatican-owned residence where he routinely stays during visits to Rome and where he stayed before the start of the conclave to pick up his luggage, pay the bill and greet staff.

"He wanted to come here because he wanted to thank the personnel, people who work in this house," said The Rev. Pawel Rytel-Andrianek, who is staying at the residence. "He greeted them one by one, no rush, the whole staff, one by one."

"People say that he never in these 20 years asked for a (Vatican) car," he said. "Even when he went for the conclave with a priest from his diocese, he just walked out to the main road, he picked up a taxi and went to the conclave. So very simple for a future pope."

Francis displayed that same sense of simplicity and humility immediately after his election, shunning the special sedan that was to transport him to the hotel so he could ride on the bus with other cardinals, and refusing even an elevated platform from which he would greet them, according to U.S. Cardinal Timothy Dolan.

"He met with us on our own level," Dolan said.

"I think we're going to see a call to Gospel simplicity," said U.S. Cardinal Donald Wuerl. "He is by all accounts a very gentle but firm, very loving but fearless, a very pastoral and caring person ideal for the challenges today."

During dinner, Francis, however, acknowledged the daunting nature of those challenges in a few words addressed to the cardinal electors: "`May God forgive you for what you have done,'" Francis said, according to witnesses.

The Vatican spokesman the Rev. Federico Lombardi acknowledged the difference in style between the two popes, attributing it to Francis' life work as the pastor of Buenos Aires whereas Benedict was long an academic. He said it was too early to make a "profound evaluation" of Francis' priorities, urging instead reflection on his first few homilies - particularly at his installation Mass on Tuesday.

The 76-year-old Bergoglio, said to have finished second when Pope Benedict XVI was elected in 2005, was chosen on just the fifth ballot to replace